net: microchip: sparx5: Add VCAP admin locking in debugFS

This ensures that the admin lock is taken before the debugFS functions
starts iterating the VCAP rules.
It also adds a separate function to decode a rule, which expects the lock
to have been taken before it is called.
Signed-off-by: Steen Hegelund <steen.hegelund@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/microchip/vcap/vcap_api.c

@@ -2170,47 +2170,53 @@ void vcap_free_rule(struct vcap_rule *rule)
 }
 EXPORT_SYMBOL_GPL(vcap_free_rule);
 
-struct vcap_rule *vcap_get_rule(struct vcap_control *vctrl, u32 id)
+/* Decode a rule from the VCAP cache and return a copy */
+struct vcap_rule *vcap_decode_rule(struct vcap_rule_internal *elem)
 {
-	struct vcap_rule_internal *elem;
 	struct vcap_rule_internal *ri;
 	int err;
 
-	ri = NULL;
-
-	err = vcap_api_check(vctrl);
-	if (err)
-		return ERR_PTR(err);
-	elem = vcap_lookup_rule(vctrl, id);
-	if (!elem)
-		return NULL;
-	mutex_lock(&elem->admin->lock);
 	ri = vcap_dup_rule(elem, elem->state == VCAP_RS_DISABLED);
 	if (IS_ERR(ri))
-		goto unlock;
+		return ERR_PTR(PTR_ERR(ri));
 
 	if (ri->state == VCAP_RS_DISABLED)
-		goto unlock;
+		goto out;
 
 	err = vcap_read_rule(ri);
-	if (err) {
-		ri = ERR_PTR(err);
-		goto unlock;
-	}
+	if (err)
+		return ERR_PTR(err);
+
 	err = vcap_decode_keyset(ri);
-	if (err) {
-		ri = ERR_PTR(err);
-		goto unlock;
-	}
+	if (err)
+		return ERR_PTR(err);
+
 	err = vcap_decode_actionset(ri);
-	if (err) {
-		ri = ERR_PTR(err);
-		goto unlock;
-	}
+	if (err)
+		return ERR_PTR(err);
 
-unlock:
+out:
+	return &ri->data;
+}
+
+struct vcap_rule *vcap_get_rule(struct vcap_control *vctrl, u32 id)
+{
+	struct vcap_rule_internal *elem;
+	struct vcap_rule *rule;
+	int err;
+
+	err = vcap_api_check(vctrl);
+	if (err)
+		return ERR_PTR(err);
+
+	elem = vcap_lookup_rule(vctrl, id);
+	if (!elem)
+		return NULL;
+
+	mutex_lock(&elem->admin->lock);
+	rule = vcap_decode_rule(elem);
 	mutex_unlock(&elem->admin->lock);
-	return (struct vcap_rule *)ri;
+	return rule;
 }
 EXPORT_SYMBOL_GPL(vcap_get_rule);
 

drivers/net/ethernet/microchip/vcap/vcap_api_debugfs.c

@@ -295,7 +295,7 @@ static int vcap_show_admin(struct vcap_control *vctrl,
 
 	vcap_show_admin_info(vctrl, admin, out);
 	list_for_each_entry(elem, &admin->rules, list) {
-		vrule = vcap_get_rule(vctrl, elem->data.id);
+		vrule = vcap_decode_rule(elem);
 		if (IS_ERR_OR_NULL(vrule)) {
 			ret = PTR_ERR(vrule);
 			break;
@@ -404,8 +404,12 @@ static int vcap_debugfs_show(struct seq_file *m, void *unused)
 		.prf = (void *)seq_printf,
 		.dst = m,
 	};
+	int ret;
 
-	return vcap_show_admin(info->vctrl, info->admin, &out);
+	mutex_lock(&info->admin->lock);
+	ret = vcap_show_admin(info->vctrl, info->admin, &out);
+	mutex_unlock(&info->admin->lock);
+	return ret;
 }
 DEFINE_SHOW_ATTRIBUTE(vcap_debugfs);
 
@@ -417,8 +421,12 @@ static int vcap_raw_debugfs_show(struct seq_file *m, void *unused)
 		.prf = (void *)seq_printf,
 		.dst = m,
 	};
+	int ret;
 
-	return vcap_show_admin_raw(info->vctrl, info->admin, &out);
+	mutex_lock(&info->admin->lock);
+	ret = vcap_show_admin_raw(info->vctrl, info->admin, &out);
+	mutex_unlock(&info->admin->lock);
+	return ret;
 }
 DEFINE_SHOW_ATTRIBUTE(vcap_raw_debugfs);
 

drivers/net/ethernet/microchip/vcap/vcap_api_private.h

@@ -118,4 +118,7 @@ int vcap_find_keystream_keysets(struct vcap_control *vctrl, enum vcap_type vt,
 /* Get the keysets that matches the rule key type/mask */
 int vcap_rule_get_keysets(struct vcap_rule_internal *ri,
 			  struct vcap_keyset_list *matches);
+/* Decode a rule from the VCAP cache and return a copy */
+struct vcap_rule *vcap_decode_rule(struct vcap_rule_internal *elem);
+
 #endif /* __VCAP_API_PRIVATE__ */